Research And Application Of Grey Theory Of Early Rapid Presumption In Concrete Strength

Compressive strength of concrete indicators are the core content of the qualitycontrol of concrete, compressive strength of concrete structural members is determinedin accordance with the existing norms need28days, how fast and accurately in advancepredict the28-day strength of the concrete is particularly important in the prosperousperiod of the construction industry, construction progress continues to accelerate, theconstruction cycle is becoming shorter and shorter.Based on the analysis of the strength of concrete theory and gray system theory, theadaptability of the gray theory in the early and rapid estimation of concrete strength inadvance was qualitatively verified and the28-day strength prediction model of ordinaryconcrete and high-strength concrete were quantitatively given, according to concretecompressive strength test data, gray sequence operator theory, gray GM (1,1) modeltheory and gray prediction theory. This could provide a basis for the prediction ofconcrete strength in advance and guidance of the quality of the construction process.This paper mainly includes the following aspects:①Methods and their characteristics of quickly presume early28-day strength ofthe concrete at home and abroad; An overview of the application status of the concretestrength theory, gray theory and its application in concrete.②The theory of concretestrength was analyzed in three aspects: concretecomposition and micromechanical structure, concrete force-deformation mechanismand concrete calculation under force; The basic concepts of gray system theory and themain content, its basic principles and the characteristics of early concrete strength ingray system were introduced.③The GM (1,1) model was carried out, the general GM (1,1) model modelingsteps were summed up, and the method of examination and treatment of the originalsequence were given in advance, as well as the methods of the accuracy of the modelwere evaluated.④The original experimental data was processed with average Weakening Buffer,weighted average Weakening Buffer and geometric mean Weakening Buffer; Based onthe Original experimental data and the sequence of three weakening process,6-dimensional GM (1,1) model, according to a time interval of0.5day (total3days)aswell as1day(total6days), were established. The prediction of concrete28-day strength respectively carried out through the6-dimensional GM (1,1) models on the ordinaryconcrete and the high-strength concrete; The degree of coincide of the predicted valueand the actual experimental data was analyzed through the reduction of the respectivemodel forecast data, eventually come to the best predictor of the concrete strength GM(1,1) model.